Essential Insights On Treating Retrocalcaneal Exostosis

The management of posterior heel pain can be a perplexing diagnostic and therapeutic problem. The differential diagnosis is extensive and even the skilled clinician can experience difficulty establishing an accurate diagnosis. Of the challenging conditions affecting the back of the heel, the retrocalcaneal exostosis may be the most onerous to treat.

Unlike Haglund’s deformity, which is generally a posterior-superior or posterior-superior-lateral prominence, the “true” retrocalcaneal exostosis involves an intratendinous component. This is often considered a distal insertional Achilles enthesiopathy. To remove the exostosis or “spur,” the surgical approach must include incision through at least a portion of the tendinous substance of the Achilles tendon.

Accordingly, let us take a closer look at a technically simplified, reproducible method for treating this most arduous condition.

The clinical presentation of the patient with a retrocalcaneal exostosis or insertional spurring within the Achilles tendon is very similar to that of the patient suffering from a Haglund’s deformity.

Keys To Recognizing And Differentiating The Clinical Presentation

The patient will typically complain of a prominence of the posterior heel associated with pain, tenderness, erythema and edema that may increase with activity or certain types of shoes. Typically, the patient experiences a dull, aching pain with localized tenderness near the insertion of the Achilles tendon. Occasionally, one may note a palpable “hardness” or “thickening” in the Achilles tendon just proximal to its insertion into the calcaneus. This might represent concomitant calcification of the tendon itself or, more likely, degenerative changes associated with partial tendon rupture. The patient often complains of what Cicchinelli described as a “bulky posterior heel.”1

Patient ages range from the early 20s to the 80s. However, the presentation is more common in middle-aged or older patients, and is more common in obese or poorly conditioned patients. Younger patients who present with the condition are usually involved in athletics or are obese. The condition is more common in women and is most likely secondary to the shoe styles they tend to wear.2-4

The retrocalcaneal exostosis or spurring within the insertion of the Achilles tendon can occur concomitantly with a Haglund’s deformity, retrocalcaneal bursitis, Achilles tendinitis, ankle equinus or plantar heel spur syndrome. One should take care to distinguish among these conditions.

Podiatrists can best accomplish this differentiation by assiduous clinical palpation and radiographic evaluation. Identify the painful retrocalcaneal exostosis with direct palpation of the insertional area of the tendo-Achilles. Generally, this will be the point of maximum tenderness although the patient may have pain that extends around this area. The pain may be aggravated by passive and active ankle joint range of motion, especially dorsiflexion.

The role of ankle equinus in this condition is difficult to state with certainty but it is often associated with this condition. The general lack of flexibility of the insertional area of the tendon may simply be present throughout the entire tendon structure. Radiographically, a standard lateral view will demonstrate the retrocalcaneal exostosis, posterior calcaneal step or intratendinous spur. Magnetic resonance imaging (MRI) studies may also be helpful if thickening of the Achilles tendon is present or if one suspects chronic bursitis, tendinitis or the partial tendon rupture to be involved.

Step-By-Step Pearls On A Modified Approach To The Fowler-Philip Technique

The literature has described many surgical approaches to the retrocalcaneal exostosis and spur over the years. I have been performing a modification of the Fowler-Philip approach to the retrocalcaneal exostosis and spur since 1987. Fowler and Philip first described an inverted “Y” incision through the tendon in 1945.5 They described their rationale for this approach based upon their observations of the anatomic insertion of the Achilles tendon:

“The central portion of the tendon is inserted into the middle area on the posterior surface of the bone while the lateral parts of the tendon sweep on to the medial and lateral surfaces of the os calcis so … the central part of the tendon can be divided transversely, avoiding the lateral expansions, and when the central portion is re-sutured, there is little risk of permanently weakening the tendo-Achilles.”

I advocate either an inverted “V” or “Y” approach through the Achilles tendon in this fashion. This approach allows removal of any retrocalcaneal exostosis or insertional spur, and any intratendinous calcification present.

The surgeon can best perform the technique for the modified Fowler-Philip approach with the patient in a prone position. Typically, one would utilize general inhalation or spinal anesthesia with a mid-thigh pneumatic tourniquet. If desired or medically necessary, one can perform the procedure with

the patient in the lateral or supine position, using local anesthesia with or without a tourniquet.

The surgical approach is usually through a midline, longitudinal incision. This approach is different from what Fowler and Philip advocated. Fowler and Philip utilized a curved transverse incision with the convexity of the incision directed upward.5 I have not utilized this approach as the longitudinal approach provides better exposure of the Achilles tendon.

Carry dissection bluntly deep through the subcutaneous tissue until visualizing the deep fascia. Take care to avoid the sural nerve and the lesser saphenous vein during this dissection. With the subcutaneous tissues retracted, make a single inverted V or Y incision through the deep fascia, paratenon and tendon. Center the apex of the V at the dorsal aspect of the spur, which one can easily palpate through the tendon. Then carry the arms of the V or Y medially and laterally to the distal medial and distal lateral extents of the exostosis or spur. The arms are typically 1 to 1.5 cm in length.

If no intratendinous calcification or dystrophic tendon is present, the inverted V approach is usually sufficient. If calcification or dystrophic tendon is present, convert the inverted V into an inverted Y and split the tendon more proximally in its midline to excise the calcification and/or diseased tendon fibers.

After incising the tendon, reflect the V flap distally, taking care to preserve its distal attachment. This dissection needs to proceed carefully to detach all soft tissue from bone, similar in fashion to the detachment of the capsule from the medial eminence of the first metatarsal head during bunion correction surgery. Then expose the retrocalcaneal spur, step and/or exostosis. Resect the exostosis and spur with osteotomes or power instrumentation. I generally prefer using a curved osteotome to remove the bulk of the bone and subsequently use a power reciprocating rasp or hand rasp to contour the remaining bone.

After removing an appropriate amount of bone, reanchor the tendon to bone with suture anchors. This is another modification of the Fowler and Philip procedure as they did not discuss this reattachment. I feel the reattachment strengthens the repair. The surgeon can accomplish the reattachment by suturing the tendon to bone with non-absorbable suture through drill holes or, more commonly, by using a suture anchor system to accomplish the tenodesis.

After reattaching the tendon to bone, repair the V or Y incision through deep fascia, paratenon and tendon as one layer with 2-0 absorbable and/or non-absorbable sutures. Approximate the subcutaneous tissue with a 4-0 absorbable suture and close the skin with a 5-0 absorbable or non-absorbable suture. Apply adhesive wound strips, a saline-moistened sponge, a dry sterile dressing and a below-knee Jones compression cast. One would typically take postoperative radiographs on the day of surgery or within the first postoperative week.

What You Should Know About Postoperative Care

In the immediate postoperative period, utilize a below-knee Jones compression cast to minimize edema and associated postoperative pain. The surgeon usually changes the dressing in the first five to 10 post-op days. If the edema is under control, apply a below-knee synthetic cast. Apply the cast with the ankle and subtalar joints in their neutral position.

Keep the patient non-weightbearing for four to eight weeks in the cast. If the patient continues to demonstrate edema, pain or is obese, he or she may wear a cast for a longer period. After the period of non-weightbearing immobilization, the patient gradually returns to weightbearing. This is typically accomplished with a walking synthetic cast (i.e., CAM walker type cast) for an additional three to six weeks.

Following cast removal, start appropriate rehabilitation including range of motion exercises for the ankle and subtalar joints, and strengthening exercises of the calf musculature. Continue compression with supportive material or an ankle brace until most of the edema has resolved and the patient is able to ambulate with minimal difficulty. Long-term orthoses and appropriate shoes are advised.

How To Resolve Complications

The primary complications associated with this approach are related to the Achilles tendon. Rupture of the tendon is always a possibility in any surgical approach involving temporary detachment of the tendo-Achilles. However, this is unusual if one provides proper postoperative treatment and care, and the patient is adherent.

Postoperative tendonitis of the Achilles tendon is more common. If this occurs, it typically starts when the patient begins unsupported weightbearing and gradually resolves over the next two to four months. If the tendonitis does not resolve, institute appropriate treatment similar to that for any Achilles tendonitis. If the pain continues, the clinician should reassess the posterior heel area to rule out any other conditions that might be contributing to the ongoing pain syndrome.

Sundberg and Johnson state that “excessive subcutaneous scarring” is a drawback of the classic Fowler-Philip surgical approach.6 However, the classic Fowler-Philip approach utilized a curved transverse incision through both the skin and deeper structures. In my experience, combining the posterior longitudinal skin incision with the inverted V or Y extension through the deeper structures has rarely led to any significant scarring problems. However, handling of the soft tissues in a meticulous fashion and the use of anatomic dissection cannot be overemphasized. If a postoperative wound dehiscence or painful cicatrix develops, treat those conditions in an appropriate fashion.

In Conclusion

Surgeons should not hastily decide to perform a retrocalcaneal exostectomy with reflection, debridement and reattachment of the tendo-Achilles. The procedure requires a significant postoperative recovery period and is associated with several dreaded postoperative complications. I have found the modified surgical approach, as described above, to be a simple, reproducible and reliable surgical procedure when it is indicated.

Dr. Downey is the Chief of the Division of Podiatric Surgery at Penn Presbyterian Medical Center in Philadelphia. He is also a Senior Faculty Member of the Podiatry Institute.

Dr. Burks is a Fellow of the American College of Foot and Ankle Surgeons, and is board-certified in foot and ankle surgery. He is in private practice in Little Rock, Ark.